Gordon Brown knows precisely what he should do about BP. The company's £10bn profits are crying out for a windfall tax. Royalties and petroleum revenue tax, both lifted when the oil price was low, are in urgent need of reinstatement. These measures would be popular and fair. But, as all political leaders are aware, you don't mess with Big Oil.

During the 1999 Balkans war, some of the critics of Nato's intervention alleged that the western powers were seeking to secure a passage for oil from the Caspian sea. This claim was widely mocked. The foreign secretary Robin Cook observed that "there is no oil in Kosovo". This was, of course, true but irrelevant. An eminent commentator for this paper clinched his argument by recording that the Caspian sea is "half a continent away, lodged between Iran and Turkmenistan".

For the past few weeks, a freelance researcher called Keith Fisher has been doggedly documenting a project which has, as far as I can discover, has been little-reported in any British, European or American newspaper. It is called the Trans-Balkan pipeline, and it's due for approval at the end of next month. Its purpose is to secure a passage for oil from the Caspian sea.

The line will run from the Black sea port of Burgas to the Adriatic at Vlore, passing through Bulgaria, Macedonia and Albania. It is likely to become the main route to the west for the oil and gas now being extracted in central Asia. It will carry 750,000 barrels a day: a throughput, at current prices, of some $600m a month.

The project is necessary, according to a paper published by the US Trade and Development Agency last May, because the oil coming from the Caspian sea "will quickly surpass the safe capacity of the Bosphorus as a shipping lane". The scheme, the agency notes, will "provide a consistent source of crude oil to American refineries", "provide American companies with a key role in developing the vital east-west corridor", "advance the privatisation aspirations of the US government in the region" and "facilitate rapid integration" of the Balkans "with western Europe".

In November 1998, Bill Richardson, then US energy secretary, spelt out his policy on the extraction and transport of Caspian oil. "This is about America's energy security," he explained. "It's also about preventing strategic inroads by those who don't share our values. We're trying to move these newly independent countries toward the west.

"We would like to see them reliant on western commercial and political interests rather than going another way. We've made a substantial political investment in the Caspian, and it's very important to us that both the pipeline map and the politics come out right."

The project has been discussed for years. The US trade agency notes that the Trans-Balkan pipeline "will become a part of the region's critical east-west Corridor 8 infrastructure ... This transportation corridor was approved by the transport ministers of the European Union in April 1994". The pipeline itself, the agency says, has also been formally supported "since 1994". The first feasibility study, backed by the US, was conducted in 1996.

The pipeline does not pass through the former Yugoslavia, but there's no question that it featured prominently in Balkan war politics. On December 9 1998, the Albanian president attended a meeting about the scheme in Sofia, and linked it inextricably to Kosovo. "It is my personal opinion," he noted, "that no solution confined within Serbian borders will bring lasting peace." The message could scarcely have been blunter: if you want Albanian consent for the Trans-Balkan pipeline, you had better wrest Kosovo out of the hands of the Serbs.

In July 1993, a few months before the corridor project was first formally approved, the US sent peacekeeping troops to the Balkans. They were stationed not in the conflict zones in which civilians were being rounded up and killed, but on the northern borders of Macedonia. There were several good reasons for seeking to contain Serb expansionism, but we would be foolish to imagine that a putative $600m-a-month commercial operation did not number among them. The pipeline would have been impossible to finance while the Balkans were in turmoil.

I can't tell you that the war in the former Yugoslavia was fought solely in order to secure access to oil from new and biddable states in central Asia. But in the light of these findings, can anyone now claim that it was not?

Stephen Starr: Two French oceanography researchers expected to find pollution on their 8,345km, 14-month kayak journey from Gibraltar to Istanbul – but what shocked them was the endless spread of cities along the coast